Hammers of many sizes and shapes are available throughout the prior art, and typically comprise a handle portion extending generally normal to and connected to a head potion that serves as the striking end of the hammer. It has been a prevalent practice in the trade to construct the handle portion of hammers from high grade wood. Preferably, a grade of hickory wood is used to form the handle portion because of the desirable characteristics including strength and resiliency. All woods, however, have obviously limited strength and, therefore, are subject to breakage under relatively low stress.
Recently, hammers having an internal metal or steel skeleton surrounded by a molded plastic shell have become increasingly popular. The internal metal skeleton provides the hammer with stiffness and strength while the surrounding plastic shell provides a degree of comfort during use of the hammer. Because of the high density of the steel, however, tools incorporating handles of this type have been found to have poor dynamic qualifies as proper centers of gravity and percussion cannot be obtained if other minimum practical design characteristics are to be met. Another severe drawback with hammers having steel metal skeletons is that the impact at the striking moment is transmitted through the metal hammer body to the users hand, thus increasing efforts and labor of the user and thereby reducing the operating efficiency of the hammer. Moreover, the metal hammer body tends to make the hammer heavy to use and transport.
When a percussive tool such as a hammer is moved to strike a surface of an object, part of the kinetic energy developed is utilized in doing the desired work on the object, part is dissipated as heat, and part is converted into potential energy in the form of distortion in the striking surface of the hammer. Hammer recoil has been encountered with hammer configurations including either exposed striking heads or a skeletal hammer design wherein the hammer heads are wholly received in an encasing to prevent sparking or the like during hammer use. The distortion of the striking surface of the hammer has potential energy much the same way as a compressed spring. It is this potential energy that causes the hammer to recoil or bounce back from the surface of the object being struck.
Various attempts have been proposed to provide an advantageous "dead-blow" characteristic to the hammer when the striking head thereof impacts with the surface being struck. Such a requirement resulted in forming the head portion of the hammer from lead or other suitable shock absorbing materials. These hammers have proven satisfactory for forcing large machine parts into place, but due to their soft and malleable composition have extremely abbreviated usefulness.
To prolong the usefulness of the hammer while continuing to offer the long sought "dead-blow" feel for the hammer, some designers have configured the head portion of the hammer with standard striking heads and a powdered shot filled cavity therebetween to dampen the recoil of the hammer. In an attempt to offer a hammer having advantageous "dead-blow" characteristics, another approach involves configuring the hammer head portion with a series of slidable slugs arranged behind the striking head of the hammer. A recent and innovative tool design yielding significant advantages in the ability to provide the hammer with a "dead-blow" characteristic involves configuring the head potion of the hammer with operably coupled yet split striking heads.
Thus, there is both a need and a desire for a lightweight percussive tool which provides a so called "dead-blow" characteristic by preventing rebounding of the striking head on the hammer and which reduces the impact or vibration transmitted through the tool to the user thereof.